The purpose of this project is to develop a diastolic volume limiting apparatus (divola) for treatment of advanced heart disease in humans. This technology is an entirely new method of treatment of heart disease, and may be used in both dilated and ischemic cardiomyopathy. The device is simply a plastic sac that is placed inside the left ventricle of a diseased heart, and functions by limiting filling of the ventricle during diastole. The divola protects the left ventricle from the harmful effects of high ventricular pressure during diastole, allowing for reverse remodelling (shrinkage) of a pathologically jenlarged ventricle. The device may be used in patients who would otherwise require a heart transplant or a mechanical circulatory assist device. The device may also be applied to other forms of heart disease, including left ventricular aneurysms, ischemic ventricular septal defects, and (with modification) primary pulmonary hypertension. Initial research efforts in phase I are directed to designing and testing advanced prototypes of the divola for implantation into animals. Geometric measurements will be taken from sheep echocardiograms to establish the parameters for construction of the divola. The process of fabrication of divolas will be established and refined. High speed video analysis will be used to determine ideal folding patterns and pumping action in order to minimize thrombogenicity and maximize durability. Flow visualization studies will be performed to determine the ideal shape and dimensions of the divola. The divola will be tested on a benchtop apparatus to determine durability and hemolysis. Successful Phase I research will lead to an advance design of the divola suitable for implantation and testing in large animal models of heart failiure in Phase II research. Successful development of this techology would provide a practical and inexpensive method for treatment of advance heart disease as an alternative to heart transplantation or mechanical circulatory assist devices.